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      <title>消息流量控制过滤实现 - 交互式测验</title>
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    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>消息流量控制过滤实现 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
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                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
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                    <div id="hint-container" class="hint-container"></div>
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                <div class="quiz-footer" id="quiz-footer">
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      <script>
        const quizData = [
  {
    "question": "在RocketMQ的Producer端，如果希望精细化控制异步发送消息的并发线程数量，应该配置哪个参数？",
    "options": [
      "通过设置 sendMsgTimeout 来间接控制",
      "通过调用 setAsyncSenderExecutor 方法并传入一个自定义的线程池",
      "通过调整 Broker 端的 maxMessageSize 参数",
      "通过启用故障规避机制自动调节"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档明确指出，DefaultMQProducer 提供了 setAsyncSenderExecutor 方法，允许用户自定义线程池。通过控制这个线程池的大小和行为，可以精确地管理异步发送消息的并发量，这是最直接的控制方式。",
    "source": "文档中「Producer端流量控制机制 -> 1.1 客户端限流」部分",
    "hint": "思考一下，在Java中通常如何管理一组执行异步任务的线程？文档中提到了一个与Executor相关的方法。"
  },
  {
    "question": "当RocketMQ Consumer在处理消息时，如果业务逻辑判断当前系统负载过高，无法立即处理新消息，但希望稍后能重新消费该消息，应该返回哪种消费状态？",
    "options": [
      "ConsumeConcurrentlyStatus.CONSUME_SUCCESS",
      "ConsumeConcurrentlyStatus.RECONSUME_LATER",
      "直接抛出异常，让Broker重发",
      "不返回任何状态，让其超时"
    ],
    "correctAnswerIndex": 1,
    "explanation": "返回 `ConsumeConcurrentlyStatus.RECONSUME_LATER` 是实现手动流控的关键。它告知Broker当前无法处理该消息，请求稍后重新投递。这可以有效防止在消费端负载过高时消息丢失，并实现一种“背压”效果，减缓消费速率。",
    "source": "文档中「Consumer端消费限流的方法 -> 4. 手动ACK控制」部分",
    "hint": "在手动ACK模式下，消费者需要明确告知Broker消息的处理结果。哪一个状态代表“现在不行，请稍后再试”？"
  },
  {
    "question": "根据文档，当RocketMQ Broker的磁盘使用率超过 `diskSpaceWarningLevelRatio` 阈值时，它会采取什么流控措施？",
    "options": [
      "降低Consumer拉取消息的速率",
      "自动删除CommitLog中的旧消息",
      "拒绝新的消息写入请求，以保护磁盘",
      "向所有Producer发送告警信息"
    ],
    "correctAnswerIndex": 2,
    "explanation": "为了防止系统因磁盘空间耗尽而崩溃，Broker设置了磁盘使用率阈值。一旦超过这个阈值（例如默认的90%），Broker会启动保护机制，拒绝新的消息写入。这是Broker端一种重要的自我保护和流量控制策略。",
    "source": "文档中「Broker端的流量控制策略 -> 1.2 发送消息流控」部分",
    "hint": "当存储资源即将耗尽时，系统最直接有效的保护措施是什么？"
  },
  {
    "question": "在Consumer端，哪个参数用于设置每次从Broker拉取的消息条数的最大值，从而影响消费速率？",
    "options": [
      "setPullInterval(1000)",
      "setConsumeThreadMax(30)",
      "setPullThresholdForQueue(1000)",
      "setConsumeMessageBatchMaxSize(10)"
    ],
    "correctAnswerIndex": 3,
    "explanation": "`setConsumeMessageBatchMaxSize` 参数直接定义了Consumer单次拉取请求最多能获取多少条消息。通过调整这个值，可以控制数据流入消费端的批量大小，是进行消费速率控制的常用手段之一。",
    "source": "文档中「Consumer端消费限流的方法 -> 2.1 批量消费设置」部分",
    "hint": "这个问题关注的是“数量”而非“频率”或“线程数”。寻找一个与“批量大小”相关的设置。"
  },
  {
    "question": "RocketMQ Producer端的“故障规避”机制是如何工作的？",
    "options": [
      "当某个Broker宕机时，Producer会从NameServer获取新的Broker列表",
      "当某个Broker响应变慢或失败率增高时，Producer会暂时减少向其发送消息的频率",
      "Producer会周期性地对所有Broker进行健康检查",
      "当发送消息失败时，Producer会立即将该消息转存到本地磁盘"
    ],
    "correctAnswerIndex": 1,
    "explanation": "故障规避是一种智能的路由机制。Producer会监控向各个Broker发送消息的延迟和成功率。如果发现某个Broker性能下降（响应时间长或失败率高），Producer会暂时将其放入一个“规避列表”，在选择发送队列时会跳过这个Broker，从而将流量导向健康的节点，保证整体发送的稳定性和效率。",
    "source": "文档中「Producer端流量控制机制 -> 2. 流控与背压机制」部分",
    "hint": "这个机制的目的是主动“避开”有问题的节点，而不是等待它完全宕机。"
  },
  {
    "question": "在Broker的配置文件中，`pullBatchSize` 参数的作用是什么？",
    "options": [
      "控制Producer单次批量发送消息的最大数量",
      "限制Consumer单次拉取请求能获取的最大消息条数",
      "设置CommitLog每批次写入磁盘的消息数量",
      "定义Broker内存中缓存的消息批次数"
    ],
    "correctAnswerIndex": 1,
    "explanation": "`pullBatchSize` 是Broker端的一个读取限流参数，它限制了当Consumer发起拉取请求时，Broker一次最多返回给Consumer的消息数量（默认为32条）。这个参数与Consumer端的 `consumeMessageBatchMaxSize` 共同决定了实际的批量消费大小。",
    "source": "文档中「Broker端的流量控制策略 -> 2.1 拉取消息流控」部分",
    "hint": "从参数名 “pull” 和 “batch size” 推断，它与哪个操作（拉取还是推送）和哪个方面（数量还是大小）有关？"
  },
  {
    "question": "根据文档的“实践建议”，以下哪项不属于推荐的监控与告警核心指标？",
    "options": [
      "消息堆积量",
      "Broker的操作系统版本",
      "消息发送与消费的TPS和RT",
      "Broker的CPU、内存、磁盘等资源使用率"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档的“监控与告警”部分明确列出了需要重点关注的性能和状态指标，包括TPS（每秒事务数）、RT（响应时间）、消息堆积量以及Broker的资源使用率。而Broker的操作系统版本属于静态的环境信息，通常在部署时确定，不作为衡量系统实时健康状况和触发流控告警的核心动态指标。",
    "source": "文档中「实践建议 -> 2. 监控与告警」部分",
    "hint": "监控系统通常关注的是动态变化的、能反映系统健康和负载的指标。哪个选项更像是一个静态的基础设施信息？"
  }
];
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        let score = 0;
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            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

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                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
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            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  